类：ReadableStreamDefaultController

【Class: ReadableStreamDefaultController】

每个 <ReadableStream> 都有一个控制器，负责流队列的内部状态和管理。ReadableStreamDefaultController 是用于非字节导向 ReadableStream 的默认控制器实现。

【Every <ReadableStream> has a controller that is responsible for the internal state and management of the stream's queue. The ReadableStreamDefaultController is the default controller implementation for ReadableStreams that are not byte-oriented.】